davis



finder gaunt ('Bffi JOB A. DAVIS, WATE RTOWN,'NEW YORK.

ream Patent No. 86,373, dated Februa/ry 2, 1869.

IMPROYEIWENT IN STEAM-GENERATORS.

To all whom it may concern:

Be it known that I, J 015 A. Dnvrs, of Waterto '11, in the county of Jefferson,-and State of New York, have invented certain Improvements inSteam-Boilers; and- I do hereby declare that the following, taken inconnection with the drawings which accompany and form part of thisspecification, is a description of my invention, sufficient to enablethose skilled in the art to practise it.

My invention relates to boilers for the generation of steam, and whilstintended and adapted for steamengines generally, I propose moreparticularly to use it for such an apparatus as the steam-generatorpatented tome, September 29, 1868; and

It consists in the construction of a vertical boiler, withradially-arranged chambers, all connected with and opening into acentral chamber, the radial chambers extending some distance from thesame; also, in the same, in combination with a surrounding shell orcase, which serves the double purpose of a heat-cham-' Figure 1represents a boiler made in accordance with my invention, the outercasing being shown in vertical section, in order to display the ribbedboiler encased therein;

Figure 2 is a cross-section of the boiler and its casing, taken at theline a a; of fig. 1;

Figure 3 is a vertical section of the upper part both of ribbed boilerand its casing;

Figure 4 is a cross-section of a modified form of the boiler; and

Figure 5 represents a modified construction, showing how the ribs aremade and put together when formed in pieces.

The same letters of reference indicate like parts in the differentfigures.

A is the boiler proper, which I make of anysuitable metal, eithercast'entire or formed of sheet-metal, and, g

(as shown in figs. 1, 2, 3, and 4,) ofa single piece, ex cept whereclosed at its top and bottom.

B 15,850., are hollow radial ribs, all radiating from a centralchamber,0, so that the continuous and connect-ed space enclosed by the wholeseries of ribs shall in cross-section resemble the hub and spokes of awheel. (See fig. 2.)

When cast entire, there are of course no joints in these ribs. \Vhen.made of a single piece of sheetmetal, there need be no joint in themexcept to connect the two edges of the sheet.

E is the casing, which surrounds this ribbed boiler, and serves as acontinuous band for the same, in direct contact with the extremity ofeach rib.

The same casing also forms part of the furnace, at suitable grating, F,for the fuel, being provided in the fire-chamber G, beneath the boiler.

H is a suitable water-pipe, or inlet, to supply the boiler, and I is anoutlet-pipe for the steam, both being in direct communication with theboiler.

K is a space above the boiler, and within the casing E, and

L is the outlet for the refuse products of combustion.

M is a central tube, not necessarily forming part of the construction,but which, when used, is made open at its bottom and closed at its top,and by thus serving as a central hot-air chamber, affords so muchadditional water-heating'surface.

Water being supplied to the boiler, and the fire made, it will now beseen that, relatively to the size of the boiler and of the wholeapparatus, an immenselylarge heating-surface is obtained, theratio ofwhich, (when ribbed, as shown in fig. 2,) as compared with acorrespondingly-sized boiler without such ribs, being about as twelve toone, or greater.

This ribbed form has also far greater strength in itself than a rnretube, and independent of its outer banding or casing. The ascendingcolumn of heated gases filling, as it must, all the spaces N bounded bytwo ribs and a corresponding portion of the casing, is,

as it were, closely compactedinto this wedge-shaped space, and thatportion of'it which is nearest the junction of the ribs being directlyabove and from the central and hottest portion of the fire, acts uponthe largest partof the water-heating surface of such space N, namely,upon a portion of that at the centre of the boiler, and also upon aportion of that in each of the two adjacent ribs.

This central heating of water is very largely intensifiedwhen thecentral tube M is used.

The sides I) bet each rib I prefer to make parallel shown in fig. 4, andwith or without the central heating-tube. V

I sometimes use a steam-reservoir or dome at the top of the boiler,forthe same purpose as usual, namely, to give off from the boiler drysteam.

Each hollow rib of the boiler may be made in parts, with its outer edgesbolted together; or each rib may be formed of two parts, or sides, theouter edges of each rib being bolted together, and the inner edges oftwo adjacent ribs being also bolted together, as shown in fig. 5; andwhen so constructed, it is preferable to connect the same also bystrengthening-bolts between their inner and outer ends, somewhat asshown in the V same figure.

What I claim as new, and desire to secure by Letters Patent, is-

1. The construction of the hollow radial chambers, and their combinationwith each other, substantially as herein set forth.

2. The hollow radial chambers, combined with the surrounding case orshell, in contact with the hollow radial ribs, and serving to brace theboiler, substantially as set forth.

3. The arrangement of the radial chambers B, shell

